In the field of vascular intervention, and more specifically in the field of interventional cardiology, devices known as guidewires are often used to facilitate access to a patient's vascular system, placement of various devices and/or performance of certain procedures. A guidewire is maneuvered into place to act as a guide for positioning the placement of subsequent devices “over the wire.” The guidewire, typically ranging from 0.010″ to 0.038″ inch diameter, as compared to an interventional catheter which may range from 0.040″ to 0.25″ inch diameter, is extremely flexible and tracks easily into a patient's vessels, allowing the physician to obtain an initial position, and many times to find the optimal position, in the vasculature prior to tracking a larger interventional catheter over the wire to perform an intervention. In addition, a guidewire may maintain access to a certain site in the vasculature should it be necessary for the physician to use multiple devices to perform an intervention at the site, or to perform multiple interventions at different sites in the vasculature.
Due to their flexibility, guidewire access minimizes trauma to the vessel being treated and assists in directing or guiding other devices through the curvature and tortuosity of the vascular system. Unwanted trauma may include “skiving” of the vessel, wherein a less flexible device may scrape the vessel wall at an undesired angle, and unintended perforation, wherein a device may be pushed through the vessel wall in an uncontrolled manner, leading to excessive bleeding (tamponade) and/or other severe patient complications.
Guidewires act as a rail over which other less flexible and larger diameter devices may be delivered safely, thereby reducing the risk of unwanted vessel trauma. In current medical practice, guidewire access and performance of procedures “over the wire” are the preferred mode of vascular device delivery. As such, it is critical to the clinical acceptance of new devices and therapies for them to be compatible with this technique, and to be delivered over the wire.
In light of the development of certain clinical procedures, there is a need for devices and methods that more specifically direct, place and maintain a guidewire or other rail at one or more selected locations in the vasculature.